Fuel tanks utilized for holding a supply of fuel for vehicles utilizing an internal combustion engine, are often limited in their volume and dimensions by the available space within a given area on a vehicle designated for such a purpose. With the increasing trend towards manufacturing smaller, more efficient vehicles, the available space for mounting fuel tank becomes even more limited in any given application. Due to these spatial restrictions, often times the fuel tank is specifically shaped to have a broad flat design with relatively shallow depth. These dimensions limit the mounting depth available for installing a fuel pump module having various components attached there to, for example vent valves, or emission reduction canisters, required by increasing regulations for emissions.
The alternative to having these components incorporated with the fuel pump module would be to locate them in separate apertures in the fuel tank. Unfortunately though, each additional hole increases potential fuel emission sources. Therefore it is advantageous to have a fuel pump module incorporating the sending unit, pump motor, vents, and other components into a single unitary element, reducing the need for multiple apertures through the wall of a fuel tank, and thereby limiting sources of emissions.
Fuel pump modules have been designed for a wide variety of fuel delivery applications, and have greatly improved how fuel is delivered to the engine of a vehicle. Certain pump modules utilize a reservoir as part of the fuel sending unit, as disclosed in U.S. Pat. No. 5,452,701 to Tuckey. Positioned within the fuel tank for providing a constant supply of fuel to the engine of the vehicle, these reservoirs are fed by a supply of fuel from the tank by means of a jet pump, incorporated into the main fuel pump of the sending unit.
The jet pump works to deliver fuel to the reservoir from the tank by way of a vacuum force, created by a portion of the pressurized fuel from the output of the primary fuel pump being directed through the jet pump creating a pressure gradient drawing fuel in from the tank to the reservoir. In order to maximize the efficiency of a large volume fuel tank, the jet pump and the reservoir need to be positioned adjacent the bottom or lowest portion of the fuel tank, so as to allow fuel delivery to the primary pump even in low tank fuel level situations. The problem is such, that in shallow mounting depth applications of fuel tanks, where the reservoir of the fuel pump module is directly below the modular flange, physical interference occurs between the reservoir and the components attached to the bottom of the pump modular flange.
One solution, as taught by U.S. Pat. No. 6,308,733 issued to Murakoshi, et al. is to provide for a means allowing the fuel pump reservoir to pivot away from the pump mounting flange when the unit is installed on a fuel tank. This is achieved by attaching the reservoir to the modular flange by means of a pivotal connection, thereby allowing the reservoir to deflect away horizontally from the modular flange during insertion of the pump module through the aperture located in the upper wall of a fuel tank. This provides the necessary mounting depth to fully lower the modular flange into the aperture and seal off the tank without interfering with the reservoir. Unfortunately, this pivotal joint may at times allow the reservoir to levitate off the bottom of the fuel tank even after installation, depending on how rough the conditions are of the terrain the vehicle is driving over, in turn, causing possible fuel starvation to the pump, or increased wear and eventually failure of the pivotal connection, requiring service or replacement.
The present invention overcomes the aforementioned shortcomings of prior art in utilizing compatible components of prior art fuel pump modules, to provide a modular flange and a reservoir attached offset thereto. The invention allows for the vertical insertion of the reservoir and fuel pump through the fuel tank aperture, subsequently followed by sliding of the module horizontally relative to the fuel tank so as to align the modular flange with the fuel tank aperture for attachment thereto, offset from the internal reservoir. This design significantly increases the space available for mounting extra components to the backside of the modular flange necessary to reduce emissions, while preserving the function of the fuel pump module without interference of the fuel pump reservoir.